Tung oil question

[porchdog48]

I am trying a tung oil finish on a cherry stock. I am using Woodcraft 100% tung oil. First 2 coats were deluded 50% with mineral spirits then next 2 coats 25% mineral spirits. Stock was in a 40% humidity area , and after 10 days it still feels not cured. The finish doesn’t feel tacky but feel waxy. Question is this normal , or does it need longer drying time. I am currently experimenting with adding Japan dryer on wood scrap, but still getting the waxy feel on the finish. Your thoughts would be appreciated.

Dave

[smart dog]

Hi,
You are using the wrong stuff.  Pure tung oil will take forever to dry.  At this point, I recommend that you mix your tung oil with polyurethane varnish and mineral spirits.  A mix of 25% tung oil, 25% polyurethane, and 50% mineral spirits should do the job but I am not sure how anything will work on top of your existing tung oil until it thoroughly dries.  Try putting it out in bright sun for several days.  Type in "tung oil" in the search function above and you will find many, many, many posts about tung oil finishes and the right stuff to use.

dave

[Blacksmoke]

Hi porch dog Dave,  Smart Dog is absolutely correct.  I've been using 100% tung oil for yrs. but only cut with japan dryers and this mixture only for sealing gunstocks not the final finish.  Tung oil ( even polymerized) does not finish smooth.  Under magnification it has tiny wrinkles.  You will need to work up a finish with linseed oil, Linspeed oil, polyurethane, tru oil or other commercial product .    However the tung oil will have to dry first.  I would rub as much japan dryers onto the tung oil as you can and let it dry for a few days then repeat the process.    Hope that helps,   Hugh Toenjes

[smart dog]

Hi,
Tung oil only leaves a wrinkly surface if it pools on the surface and is allowed to dry.  You don't apply tung oil like paint.  You put it on, let it sit for 10-15 minutes depending on heat and humidity, and then you wipe the excess off thoroughly.  You continue to do that and you'll end up with as smooth a finish as you could want.  The mix I mentioned will produce a much quicker drying finish but you apply the same way as I described for tung oil.  I use polymerized tung oil, which has been heat treated such that it is dry to the touch usually in 4-6 hours and ready for the next coat in 24.  The guns below are all finished with polymerized tung oil.  Not a wrinkly one among them.

dave

[porchdog48]

I am considering stripping it and starting over, but concerned that the oil that penetrate the wood will cause problems with anything I put over it. If I do strip it I will let it dry a couple weeks before a new application. Any thoughts on that approach.
Dave

[Robby]

Porchdog, Get a can of this stuff. I have been using it for fifteen years, the same quart, and have even put it on top of pure tung oil and it dries. While you are waiting for it to arrive, put your treated stock in the direct sun as long as you can, it helps.



Robby

[porchdog48]

Thanks for all your replies. At this point in time I am going to rub back finish then give it a couple weeks to further dry. I will also hang it in the sun when we have it in Ohio. I will follow up with progress. Thanks again for the help.

Regards,
Dave

[rtadams]

9-5-19

smart dog,

At your convenience would you provide the specific manufacture of the "polymerized tung oil, which has been heat treated" and any other components that you use and steps in finishing a new stock. Does the finish reside on or in the surface of the wood when completed?

Best Regards,

Robert

[Goo]

Japan drier helps things harden up

[John Shaw]

Two things come to mind. First, I thin with naptha. It beats paint thinner by a mile (Thanks to Roy Dunlap). Second, varnish or polyurethane will go bad in the can after awhile since it reacts with air. I can it in 4 oz. jelly jars and it seems to last forever. I opened a can yesterday that I had canned in 2012 and it was as good as new. I hot water bath process it for a few minutes to get the air out and then screw the lid on tight and let it seal. A quick hit with a propane torch on the lid makes it easy to open.

JS

By the way, that is some beautiful work smart dog!

[smart dog]

9-5-19

smart dog,

At your convenience would you provide the specific manufacture of the "polymerized tung oil, which has been heat treated" and any other components that you use and steps in finishing a new stock. Does the finish reside on or in the surface of the wood when completed?

Best Regards,

Robert

Hi Robert,
The finish I use is from the same company that Robby shows, Sutherland-Welles. Robby shows their excellent spar varnish, which contains UV blockers and is meant for hard outdoor uses like boats.  I use their regular polymerized tung oil in medium sheen.  Although their website shows it for internal use, the only difference between it and their external finishes are the UV blockers, which I do not find necessary for gun stocks. The old BLO-varnish finishes did not have UV blockers either and they did pretty well over 200 years. I use SW because it is a very high quality product but it is also made in Vermont so I can drive an hour to the factory and get my supply. The owners always like to see my latest project so the visit is always fun and they teach me a lot about finishes.  There are other suppliers of polymerized tung oil such as Behlen, I believe.  You so have to be careful with it because it will gum in the can over time unless you reduce the air space.  I divide a quart among a bunch of small mustard jars.  I can produce almost any finish I want with it. It soaks into the wood nicely and you can do a low-sheen "oil in the wood" finish, or you can build it up over time to produce a glossy rubbed back finish, and then anything in between. You can do the same with linseed based products like Tried and True oil-varnish and Tru Oil.  I use SW tung oil because I am very familiar with it and it meets my objectives.  My usual application strategy is to thin the oil 50% with mineral spirits for the first 2 coats, which I mop on and let soak in. I let it soak for 15 minutes and make sure I wipe off any pooled excess finish with a paper towel. I let it dry 24 hours between sealing coats and then I hand rub in small amounts of unthinned oil. On warm days, it will get tacky very quickly so I wear latex gloves when hand rubbing so I don't leave finger prints. I sometimes add a tiny bit of raw oil to slow down drying when hand rubbing.  If I want to build up a finish to a gloss to be rubbed back, I won't hand rub it. Instead, I apply it with a rag or brush, let it sit for 15 minutes, and wipe off excess completely with a paper towel. That will build a finish in the wood and on the surface more quickly than hand rubbing.  So much depends on my objectives for the piece.  If my stock is walnut, English or black, I apply the first thinned coats with 220 sand paper and sand it as I apply creating a slurry on the wood.  I let that slurry dry to a crust and then sand it smooth. Then I apply oil by hand rubbing or wiping after that.  The slurry fills the open grain on walnut very quickly.

dave       

[rtadams]

9-6-19

smart dog,

Thanks so very much for your prompt reply. The finishing explanation and material used are exactly what I needed to replicate your style of stock finish on Black and English walnut.

Best Regards,

Robert

[smart dog]

Hi Robert,
I need to give credit where credit is due.  Taylor Sapergia is the person from whom I learned to finish walnut. 

dave

[RJD-VT]

Dave,
   Thanks for all information listed above. I learned to finish walnut like you described back in GS school decades ago, but only with tru oil. I have never been real happy with it and have been wanting to try something different. SW tung oil seems like just what I was looking for.
   I wasn’t aware that it was made in N Hyde Park. That’s an easy road trip. Im about 50 miles NE of you up in Wheelock.

Two questions if you don’t mind:
How long does the tung oil last in the mustard Jars?
Also, do you use just one application during the slurry-sand or do you let it dry and do it one more time?

Thanks again, Bob D.

[smart dog]

Hi Bob,
Hello fellow Vermonter!  I've been to Wheelock.  You probably know Dave Pike up in Cabot.  I enjoy the woodswalk he puts on every year.  To answer your questions, in the mustard jars the self life is very long (years) if unopened.  Once air space develops it can be months.  Small mustard jars usually contain enough for 2 guns so I go through a jar long before it congeals.  The number of coats of "slurry" depends on the wood.  That late flint English rifle I posted only needed one coat.  I had another less dense English walnut stock that needed 2 coats because it had very open grain.

dave   

[Clark Badgett]

I've been using Pure tung oil to refinish older military stocks for a few years now, also did my trade gun stock this same way. After they are properly degreased and dried, I brush on a heavy coat, let it sit for about an hour, then I wipe off as dry as possible. I've never had any coat take more than a day or two to completely dry with this method. Any additional coats are hand rubbed hard if I want to add more. I have never cut it with anything.

Sunlight helps too.

[P.W.Berkuta]

I use Bloxygen which is an inert gas sold by Woodcraft. You spray a little into the container of finish just as you seal up the container. The inert gas replaces air in the container so the finish last much much longer. Works for me .

[Robby]

P.W., I've been using that can I posted for years and the top no longer seals it up, so I just poke my finger through the membrane that has formed on the surface and start rubbing it in. As far as the quality of the product to date I see no difference, though it has taken a deep ruby color to it, which to me, adds to the depth and character of the wood.
Robby

[Daryl]

Hi Robert,
I need to give credit where credit is due.  Taylor Sapergia is the person from whom I learned to finish walnut. 

dave

Never heard of him.